10. _Barrow._--I will, however, first mention one other writer who may, in more than one way, be regarded as the predecessor of Newton. I speak of Isaac Barrow, whom Newton succeeded as Professor of Mathematics in the University of Cambridge, and who in his mathematical speculations approached very near to Newton's method of Fluxions. He afterwards (in 1673) became Master of Trinity College, which office he held till his death in 1677. But the passages which I shall quote belong to an earlier period, (when Barrow was about 22 years old,) and may be regarded as expressions of the opinions which were then current among active-minded and studious young men. They manifest a complete familiarity with the writings both of Bacon and of Descartes, and a very just appreciation of both. The discourse of which I speak is an academical exercise delivered in 1652, on the thesis _Cartesiana hypothesis haud satisfacit præcipuis naturæ phænomenis_. By the "Cartesian hypothesis," he does not mean the hypothesis that the planets are moved by vortices of etherial matter: I believe that this Cartesian tenet never had any disciples in England; it certainly never took any hold of Cambridge. By the Cartesian hypothesis, Barrow means the doctrine that all the phenomena of nature can be accounted for by matter and motion; and allowing that the motions of the planets are to be so accounted for, (which is Newtonian as well as Cartesian doctrine,) he denies that the Cartesian hypothesis accounts for "the generations, properties, and specific operations of animals, plants, minerals, stones, and other natural bodies," in doing which he shows a sound philosophical judgment. But among the parts of this discourse most bearing on our present purpose are those where he mentions Bacon. "Against Cartesius," he says, "I pit the chymists and others, but especially as the foremost champion of this battle, our Verulam, a man of great name and of great judgment, who condemned this philosophy before it was born." "He," adds Barrow, "several times in his _Organon_, warned men against all hypotheses of this kind, and noticed beforehand that there was not much to be expected from those principles which are brought into being by violent efforts of argumentation from the brains of particular men: for that, as upon the phenomena of the stars, various constructions of the heavens may be devised, so also upon the phenomena of the Universe, still more dogmas may be founded and constructed; and yet all such are mere inventions: and as many philosophies of this kind as are or shall be extant, so many fictitious and theatrical worlds are made." The reference is doubtless to Aphorism LXII. of the First Book of the _Novum Organon_, in which Bacon is speaking of his "Idols of the Theatre." After making the remark which Barrow has adopted, Bacon adds, "Such theatrical fables have also this in common with those of dramatic poets, that the dramatic story